Scheme for realizing communications through external network from contents processing device connected to local network in home environment

ABSTRACT

A scheme for realizing communications through an external network such as telephone network from a contents processing device such as AV device or PC connected to a local network such as home network is disclosed. The contents processing device solicits a set up of connection to the server device through the telephone network, to a gateway device which is connected with both the home network and the telephone network. Then, the gateway device carries out a call set up with respect to a specified address on the telephone network, upon receiving the solicitation from the contents processing device, and transfers data transmitted from the contents processing device to a connection established by the call set up, and data arriving from the connection established by the call set up to the contents processing device.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a contents processing device forwhich there is a need to carry out communications with a server devicelocated outside a local network to which the contents processing deviceis normally connected, and a gateway device for providing a service tomediate such communications on behalf of the contents processing device.

[0003] 2. Description of the Background Art

[0004] Recently the rapid progresses of communication technology such asInternet and digital technology such as DVD (Digital Video Disk) areattracting much attentions from a variety of fields. These technologiesare beginning to spread beyond the field of information communication tofields such as broadcasting, AV (Audio Visual) devices, home appliances,etc., and it is expected that the merging of various fields mentionedabove will also progress rapidly in future.

[0005] In particular, even for a home where no sophisticatedcommunication technology has been necessary up until now, the abovenoted progress of the communication technology is giving rise to newtechnologies such as applications to the data communication technologybased on advance of the modem technology, to the home network technologysuch as IEEE 1394, etc.

[0006] Now, when further progresses in the digitalization and thenetworking of AV devices are made in future, there will arise a problemregarding handling of digital contents. Namely, there will be problemsof improper copying or improper processing of the digital contents.

[0007] For this reason, there has been a proposition of a scheme forapplying the cryptographic techniques to the above noted digitalcontents such that replay of digital contents is permitted only to thosedevices which are registered in advance.

[0008] There has also been a proposition of a scheme called Divx schemein which the fact that the contents have been replayed is remembered bythe AV device and a log history is notified to a charging server lateron so as to realize the charging with respect to the replay, in additionto the above noted replay permission control. There are also manypropositions of various other schemes such as a scheme for permittingreplay only when the replay condition is satisfied, a scheme forpermitting replay by obtaining a permission from an external licenseserver even when the replay condition is not satisfied, and so on.

[0009] These schemes require the AV device to have a network functionsuch that the required procedure can be carried out as the AV devicecarries out communications with a license server/charging server locatedon a public network.

[0010] Also, many of the future AV devices such as Internet TV and pushbutton news delivery are expected to be those that presuppose thenetworking. Presently, a telephone network is the only available networkinfra-structure that is sufficiently developed up to the homeenvironment, so that it is reasonable to expect that the communicationswith servers such as license server, charging server, news server, WWWserver, etc. will be carried out through the telephone network exceptfor some highly advanced environment.

[0011] However, the future AV devices to be introduced into the home areexpected to have interfaces to a home network such as IEEE 1394. If sucha future AV device is also to be connected to the telephone network asdescribed above, it would become necessary to provide wirings for thehome network and wirings for the telephone network connection so thatthe future AV device would inevitably become very complicated.

[0012] The same problem also arises when there is a need for a deviceconnected to a local network to carry out communications with anotherdevice through a network other than that local network.

SUMMARY OF THE INVENTION

[0013] It is therefore an object of the present invention to provide agateway device which enables a contents processing device such as AVdevice that is connected to a local network such as home network tocarry out communications through an external network such as telephonenetwork even when no interface to the external network is provided inthe contents processing device.

[0014] It is another object of the present invention to provide acontents processing device such as AV device which is capable ofcarrying out communications with an external network such as telephonenetwork by being connected to a local network such as home network evenwhen no interface to the external network is provided therein.

[0015] According to one aspect of the present invention there isprovided a gateway device, comprising: a first network interface forconnection to a home network; a second network interface for connectionto a telephone network; a call set up unit for carrying out a call setup with respect to a specified address on the telephone network, uponreceiving a solicitation for a call set up with respect to the specifiedaddress on the telephone network from a contents processing deviceconnected to the home network; and a transfer unit for transferring datatransmitted from the contents processing device to a connectionestablished by the call set up, and data arriving from the connectionestablished by the call set up to the contents processing device.

[0016] This gateway device can be a home gateway, for example. Thecontents information device can be an AV device such as DVD player or aPC, for example. The home network can be a local network such as that ofIEEE 1394 bus, for example. The telephone network can be a publicnetwork in general, and the address on the telephone network can begiven by a telephone number. The address specified by the contentsprocessing device can be that of the license server, for example.

[0017] In this aspect of the present invention, it becomes possible forthe contents processing device to carry out communications with theserver device indicated by the specified address on the telephonenetwork through the home network, so that it is not absolutely necessaryfor the contents processing device to have an interface to the telephonenetwork (public network interface) and therefore it is possible torealize a considerable simplification of network wirings.

[0018] Also, in this gateway device, the call set up unit may receivethe solicitation made by the contents processing device which has a needto communicate with the specified address in order to process a specificcontents information.

[0019] Here, the need to communicate with the specified address arises,for example, when there is a need to obtain a permission (such as thatgiven by charging or that given by license contract) for applying someprocessing such as decryption or replay to a specific contentsinformation at the contents processing device, and this permission is tobe obtained by communicating with the license server through thetelephone network.

[0020] Also, this gateway device may further comprises a notificationunit for notifying that the gateway device is in a state capable ofresponding to the solicitation, through the home network.

[0021] For example, when the second network interface is not connectedto the telephone network, this gateway device is not in a state capableof responding to the solicitation, so that this notification is notmade.

[0022] This notification can be made from this gateway device to thedevices connected to the home network either actively by using theservice location protocol, for example, or passively by writinginformation to be notified into an IEEE 1212 register, for example (soas to create a state where a device connected to the home network canlearn this information by accessing the IEEE 1212 register).

[0023] In this way, the contents processing device can recognize thecase where it is possible to make the connection to the telephonenetwork through this gateway device and the case where it is not.

[0024] According to another aspect of the present invention there isprovided a contents processing device, comprising: a network interfacefor connection to a home network; a protocol processing unit forexecuting protocol processing for communications with a server devicethrough a telephone network; a solicitation unit for soliciting a set upof connection to the server device through the telephone network, to agateway device which is connected with both the home network and thetelephone network; and a contents processing unit for processingcontents information according to the communications with the serverdevice.

[0025] In this contents processing device, this protocol processing unitcan carry out the prescribed procedure by communicating with the serverdevice through the gateway device even when the contents processingdevice does not have an interface to the telephone network.

[0026] This contents processing device can be an AV device such as DVDplayer or a PC, for example. The server device can be a license server,for example, and the gateway device can be a home gateway, for example.The home network can be a local network such as that of IEEE 1394 bus,for example, and the telephone network can be a public network ingeneral. The address on the telephone network can be given by atelephone number.

[0027] In this aspect of the present invention, the communications withthe server device can be carried out through the home network, so thatthere is no need to provide an interface to the telephone network(public network interface) in this contents processing device andtherefore it is possible to realize a considerable simplification of thedevice configuration. In addition, it becomes possible to solicit a setup of connection to the server device with respect to the gatewaydevice, so that this contents processing device and the server devicecan be connected through the home network, the gateway device, and thetelephone network and it becomes possible to carry out mutualcommunications through them.

[0028] Also, this contents processing device may further comprises anadditional network interface for connection to the telephone network;and a Judgement unit for Judging whether the communications with theserver device through the additional network interface is possible ornot; wherein the solicitation unit solicits the set up of connection tothe server device through the telephone network and the protocolprocessing unit carries out the communications with the server devicethrough the gateway device, when the judgement unit Judged that thecommunications with the server device through the additional networkinterface is not possible.

[0029] In this case, it becomes possible to carry out the communicationswith the server device through the home network so that thecommunications can be carried out through the telephone network when itis connected to the telephone network or through the home network whenit is not connected to the telephone network.

[0030] In addition, the gateway device can establish the connection tothe server device, so that this contents processing device and theserver device can be connected through the home network, the gatewaydevice, and the telephone network and it becomes possible to carry outmutual communications through them.

[0031] Also, in this contents processing device, the protocol processingunit may carry out a prescribed procedure using the communications withthe server device in order to obtain a permission to process a specificcontents information, when a need to obtain a permission to process thespecific contents information arises.

[0032] The specific contents information can be contents informationsuch as video image, still image, audio, text file, program, etc., andthe processing can be decrypting, replaying, displaying, reading,storing, copying, executing, etc.

[0033] Also, in this contents processing device, the contents processingunit may read out the specific contents information from a prescribedstorage medium, and the protocol processing unit may obtain an addressinformation of the server device which is to be used in setting upconnection to the server device, which is recorded along with thespecific contents information in the prescribed storage medium.

[0034] In this way, it becomes possible to require the charging or thelicense contract in conjunction with the reading or the copying, forexample, in order to protect the copyright of the specific contentsinformation. In addition, it becomes possible to specify differentserver devices for different storage media.

[0035] Also, in this contents processing device, the protocol processingunit may authenticate the address information using an authenticationinformation for the address information which is also recorded in theprescribed storage medium, before obtaining the address information.

[0036] The authentication information is obtained by encrypting theaddress information or a digest of the address information using aprescribed key.

[0037] In this way, it becomes possible to recognize whether the addressinformation is a proper one or not, that is, whether it is a properaddress information written by an organization which manufactured orproduced the storage medium, so that the user can avoid a possibility ofsetting up a connection to an incorrect server device and receivingunnecessary charges.

[0038] Also, in this contents processing device, the protocol processingunit may obtain the address information by decrypting an encryptedaddress information which is recorded in the prescribed storage medium.

[0039] The address information is encrypted using the master key that issafely stored inside this contents processing device, for example.

[0040] In this way, it becomes possible to conceal the location of theaddress information, so that the unnecessary traffic to the serverdevice can be reduced, and damages due to the so called misdialing tothe server device or the annoying calls (annoying accesses) can bereduced.

[0041] Also, in this contents processing device, the protocol processingunit may execute the protocol processing by executing a communicationprotocol program which is recorded in the prescribed storage mediumalong with the specific contents information.

[0042] In this way, it becomes possible to require the charging or thelicense contract in conjunction with the reading or the copying, forexample, in order to protect the copyright of the specific contentsinformation. In addition, it becomes possible to carry out the procedurefor the charging or the license contract using different communicationprotocols for different server devices or different storage media.

[0043] Also, in this contents processing device, the protocol processingunit may execute the communication protocol program by decrypting anencrypted communication protocol program which is recorded in theprescribed storage medium.

[0044] The communication protocol program is encrypted using the masterkey which is safely stored inside this contents processing device.

[0045] In this way, it is possible to conceal the communication protocolalgorithm, so that it becomes possible to reduce the improper access tothe server device or improper license updating by improper procedurewith respect to the storage medium.

[0046] Also, in this contents processing device, the protocol processingunit may execute the protocol processing by executing one communicationprotocol program that is executable at the contents processing deviceamong a plurality of communication protocol programs of identicalfunction written in different programming languages which are recordedin the prescribed storage medium along with the specific contentsinformation.

[0047] The programming languages can be JAVA, visual basic script, etc.

[0048] In this way, even when it is not possible to anticipate the typeof the software platform of the contents processing device at which thestorage medium is to be utilized, it becomes possible to deal with aplurality of potential platforms, so that it is possible to enhance arange of the contents processing device at which the storage medium canbe utilized.

[0049] Also in this contents processing device, the protocol processingunit may execute said one communication protocol program by decrypting acorresponding one encrypted communication protocol program which isrecorded in the prescribed storage medium.

[0050] The communication protocol program is encrypted using the masterkey which is safely stored inside this contents processing device.

[0051] In this way, it is possible to conceal the communication protocolalgorithm, so that it becomes possible to reduce the improper access tothe server device or improper license updating by improper procedurewith respect to the storage medium.

[0052] Also, in this contents processing device, the contents processingunit may utilize contents information recorded in a prescribed storagemedium when a replay condition recorded in the prescribed storage mediumis satisfied or when a permission regarding contents informationutilization is obtained through a prescribed procedure.

[0053] In addition, this contents processing device may furthercomprises: an extraction unit for extracting an address information ofthe server device to be communicated with in order to obtain thepermission when the replay condition recorded in the prescribed storagemedium is not satisfied; wherein the solicitation unit solicits the setup of connection to the server device according to the addressinformation extracted by the extraction unit, and the protocolprocessing unit carries out the prescribed procedure for obtaining thepermission from the server device through the connection established bythe gateway device in response to a solicitation by the solicitationunit.

[0054] In this way, it becomes possible to require the charging or thelicense contract in conjunction with the reading or the copying, forexample, in order to protect the copyright of the contents informationrecorded in the storage medium. In addition, it becomes possible tospecify different server devices for different storage media.

[0055] Also, in this contents processing device, the protocol processingunit may carry out the prescribed procedure by executing a communicationprotocol program which is recorded in the prescribed storage mediumalong with the contents information.

[0056] In this way, it becomes possible to require the charging or thelicense contract in conjunction with the reading or the copying, forexample, in order to protect the copyright of the contents informationrecorded in the storage medium. In addition, it becomes possible tocarry out the procedure for the charging or the license contract usingdifferent communication protocols for different server devices ordifferent storage media.

[0057] According to another aspect of the present invention there isprovided a gateway device, comprising: a first network interface forconnection to a local network; a second network interface for connectionto an external network; a call set up unit for carrying out a call setup with respect to a specified address on the external network, uponreceiving a solicitation for a call set up with respect to the specifiedaddress on the external network from a contents processing deviceconnected to the local network; and a transfer unit for transferringdata transmitted from the contents processing device to a connectionestablished by the call set up, and data arriving from the connectionestablished by the call set up to the contents processing device.

[0058] According to another aspect of the present invention there isprovided a contents processing device, comprising: a network interfacefor connection to a local network; a protocol processing unit forexecuting protocol processing for communications with a server devicethrough an external network; a solicitation unit for soliciting a set upof connection to the server device through the external network, to agateway device which is connected with both the local network and theexternal network; and a contents processing unit for processing contentsinformation according to the communications with the server device.

[0059] According to another aspect of the present invention there isprovided a gateway device, comprising: a first network interface forconnection to a first network; a second network interface for connectionto a second network different from the first network; a call set up unitfor carrying out a call set up with respect to a specified address onthe second network, upon receiving a solicitation for a call set up withrespect to the specified address on the second network from a contentsprocessing device connected to the first network; and a transfer unitfor transferring data transmitted from the contents processing device toa connection established by the call set up, and data arriving from theconnection established by the call set up to the contents processingdevice.

[0060] According to another aspect of the present invention there isprovided a contents processing device, comprising: a network interfacefor connection to a first network; a protocol processing unit forexecuting protocol processing for communications with an external devicethrough a second network different from the first network; asolicitation unit for soliciting a set up of connection to the externaldevice through the second network, to a gateway device which isconnected with both the first network and the second network; and acontents processing unit for processing contents information accordingto the communications with the external device.

[0061] It is to be noted that the present invention as described abovein terms of the gateway device and the contents processing device may beconstrued in terms of methods of operations in the respective devices.Also, the gateway device and the contents processing device of thepresent invention may be realized in forms of computer readablerecording media recording programs for causing the computer to executethe operations in the respective device by controlling appropriatehardware.

[0062] Other features and advantages of the present invention willbecome apparent from the following description taken in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0063]FIG. 1 is a schematic block diagram showing an exemplary overallconfiguration of a network system according to one embodiment of thepresent invention.

[0064]FIG. 2 is a block diagram showing an exemplary internalconfiguration of a DVD player in the network system of FIG. 1.

[0065]FIG. 3 is a diagram showing an exemplary configuration ofinformation recorded on a DVD to be set on the DVD player of FIG. 2.

[0066]FIG. 4 is a diagram showing an exemplary format of a licenseserver address description that can be used in the information shown inFIG. 3.

[0067]FIG. 5 is a flow chart of an exemplary connection set up procedureby a telephone server procedure unit in the DVD player of FIG. 2.

[0068]FIG. 6 is a sequence chart of an exemplary communication sequenceto be used in the network system of FIG. 1.

[0069]FIG. 7 is a flow chart of an exemplary operation sequence of theDVD player of FIG. 2 according to the communication sequence of FIG. 6.

[0070]FIG. 8 is a flow chart of an exemplary operation sequence of ahome gateway in the network system of FIG. 1 according to thecommunication sequence of FIG. 6.

[0071]FIG. 9 is a flow chart of a service registration procedure at ahome gateway in the network system of FIG. 1.

[0072]FIG. 10 is a block diagram showing an exemplary internalconfiguration of a home gateway in the network system of FIG. 1.

[0073]FIG. 11 is a diagram showing another exemplary configuration ofinformation recorded on a DVD to be set on the DVD player of FIG. 2.

[0074]FIG. 12 is a diagram showing another exemplary configuration ofinformation recorded on a DVD to be set on the DVD player of FIG. 2.

[0075]FIG. 13 is a diagram showing another exemplary configuration ofinformation recorded on a DVD to be set on the DVD player of FIG. 2.

[0076]FIG. 14 is a block diagram showing another exemplary internalconfiguration of a DVD player in the network system of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0077] Referring now to FIG. 1 to FIG. 14, one embodiment of the presentinvention will be described in detail.

[0078]FIG. 1 shows an exemplary overall configuration of a networksystem according to one embodiment of the present invention.

[0079] First, an exemplary case of using IEEE 1394 bus as a localnetwork 104 as shown in FIG. 1 will be described. Note that this localnetwork 104 can be a network provided in any organization or location,but the following description will be directed to a specific case wherethe local network 104 is a home network provided in some home for thesake of concreteness.

[0080] Now consider a case where a device for handling some kind ofcontents such as AV device or computer (which will be referred to as acontents processing device hereafter) is connected to the local network,and suppose that this contents processing device has a need tocommunicate with another device through a network (external network)other than this local network, besides having at least an interface forconnection to this local network (IEEE 1394 bus 104 in FIG. 1).

[0081] In this embodiment, it is assumed that the need to communicatewith that another device arises as the contents processing deviceconnected to the local network has a need to obtain a permission forutilizing or processing contents which cannot be freely utilized orprocessed.

[0082] For example, suppose a case where the desired contents can beacquired but there is a need to satisfy a certain condition in order toapply some processing to the contents at that contents processingdevice. More specifically, for instance, it can be a case where apermission by a specific system or organization is necessary in order tocarry out any processing or some specific processing with respect to thecontents (decryption of encrypted contents, display of displayablecontents, execution of executable contents, for example), and there is aneed to obtain the permission either for free or with some charge fromthat specific system or organization by carrying out a prescribedprocedure (using communications in this example) if it has not obtainedthe permission or else a valid period of the permission is limited andthere is a need to obtain the permission either for free or with somecharge from that specific system or organization by carrying out aprescribed procedure again when the valid period expires. In eithercase, it is a case where there can be a need to carry out communicationsfor the purpose of the prescribed procedure between the contentsprocessing device and a server device or the like at the specific systemor organization in order to utilize or continue to utilize somecontents.

[0083] Note that the contents information can be any of various types ofdata such as video images, still images, audio, video images or stillimages accompanied by audio, text files, programs, etc., for example,and the utilization or the processing can be any of decrypting,replaying, displaying, reading, storing, copying, executing, etc., forexample. Also, the permission can be one that can be obtained for somecharge or one that can be obtained when there is a license contract, forexample, which can be used in obtaining a license information (replaycondition to be described below, for example) for enabling theutilization or the processing of the contents.

[0084] The contents processing device to be connected to the homenetwork (IEEE 1394 bus) 104 as described above can be any of a varietyof devices such as computer, VTR, TV, etc., but the followingdescription will be directed to a specific case of using a DVD player101 as shown in FIG. 1.

[0085] Also, the following description will be directed to a specificcase where a server device at the specific system or organization whichis to be a communication correspondent of this DVD player 101 is alicense server 103 as shown in FIG. 1.

[0086] In addition, the contents processing device (DVD player 101)carries out communications with the server device (license server 103)at the specific system or organization through a network (externalnetwork) other than the local network (home network 104) according tothe need, and the following description will be described to a specificcase where this network other than the local network (home network) 104is a telephone network 105 as shown in FIG. 1.

[0087] Namely, as shown in FIG. 1, the DVD player 101 is connected tothe home network 104, and the home network 103 is connected to thetelephone network 105 through a home gateway 102 which functions as atelephone server, while the license server 103 is also connected to thetelephone network 105 either directly or through other networks orgateways.

[0088] Note that the contents processing device (DVD player 101) to beconnected to the local network may or may not have an interface fordirect connection to a network other than the local network (thetelephone network 105 of FIG. 1). Here, even if it has an interface fordirect connection to a network other than the local network, it is notnecessary to have this interface actually connected.

[0089] Now, in the network system shown in FIG. 1, the DVD player 101establishes a connection with the license server 103 by making atelephone call, for example, according to the need, and carries outexchanges of a license information (replay condition to be describedbelow, for example) and a charging information if necessary. In thefollowing, this one embodiment will be described in detail in terms ofsuch a concrete example.

[0090]FIG. 2 shows an exemplary internal configuration of the DVD player101 according to this embodiment.

[0091] As shown in FIG. 2, this DVD player 101 comprises a telephonemodem 201, an IEEE 1394 interface 202, an interface selection unit 203,a telephone server procedure unit 204, a license update procedure unit205, a license judgement unit 206, a DVD drive 207, an appendinginformation extraction unit 208, a contents extraction unit 209 and adecoder 210.

[0092] First, the hardware/software configuration of this DVD player 101will be described.

[0093] This DVD player 101 has a function for decrypting encryptedcontents such that the encryption decrypted contents or information thatcan be used in obtaining the encryption decrypted contents easily willnot be received. For example, a circuit portion of the DVD drive 207,the appending information extraction unit 208, the contents extractionunit 209, the decoder 210, the license judgement unit 206 and thelicense update procedure unit 205 should preferably formed bysemiconductor chips. For instance, the circuit portion of the DVD drive207, the appending information extraction unit 208, and the contentsextraction unit 209 can be formed by a single semiconductor chip (or thecircuit portion of the DVD drive 207 can be formed independently), whilethe decoder 201 can be formed by a single semiconductor chip, and thelicense judgement unit 206 and the license update procedure unit 205 canbe formed by a single semiconductor chip. Of course there are manypossible combinations of semiconductor chips other than this, and it ispossible to form each one of the six elements by a single semiconductorchip independently, and it is also possible to form all of the sixelements by a single semiconductor chip together.

[0094] Also, this DVD player 101 can be constructed using softwarewithin a range where the security can be ensured.

[0095] Also, this DVD player 101 can be configured either in a form of astand-alone DVD player or in a form of a DVD drive connected to acomputer. In the latter case, for example, a board mounted withsemiconductor chips on which circuits for realizing a part of thefunctions of this DVD player 101 is installed into the computer, while aprogram for realizing another part of the functions of this DVD player101 is installed into the computer by reading out a recording mediumrecording the program (or by connecting a ROM in which the program iswritten) and executed at a CPU of the computer. Else, the abovedescribed semiconductor chips are connected to a CPU bus of thecomputer.

[0096] In this embodiment, it is assumed as an example that at least thelicense Judgement unit 206 and the decoder 210 are to be provided onseparate chips, and at least the license Judgement unit 206 and thelicense update procedure unit 205 are to be provided on an identicalchip. For this reason, as described below, a contents key Kc that isnecessary in decrypting the encrypted contents will be exchanged in anencrypted form between the license judgement unit 206 and the decoder210.

[0097] Next, the structure and the operation of the DVD player 101 willbe described in detail.

[0098] As shown in FIG. 2, the DVD player 101 is provided with twonetwork interfaces including the telephone modem 201 which is capable ofmaking a direct connection to the telephone network 105 and the IEEE1394 interface 202 which is capable of making a direct connection withthe home network (IEEE 1394) 104.

[0099] The interface selection unit 203 selects appropriate one of thesetwo interfaces which is actually connected to the network (the telephonemodem 201 is to be selected in the case where both of them are actuallyconnected), and supports communications by the license update procedureunit 205 through the telephone network 105 or the home network 104 (andthe home gateway 102 and the telephone network 105).

[0100] The telephone server procedure unit 204 functions to establish aconnection with the license server 103 as will be described in detaillater.

[0101] The DVD drive 207 is a disk drive for reading information from orwriting information into a DVD that is set thereon.

[0102] Here, the DVD (DVD-RAM, for example) to be set on the DVD drive207 is assumed to have an exemplary configuration as shown in FIG. 3.Namely, the DVD records contents 301 such as video that is encryptedusing the contents key Kc in advance, and an appending information 302that is encrypted using a master key Km.

[0103] Note that, in the following, data encrypted using a key Ki willbe denoted as [data]Ki. For example, the contents encrypted using thecontents key Kc will be denoted as [Contents]Kc, and the appendinginformation encrypted using the master key Km will be denoted as[Appending Information]Km.

[0104] In the exemplary configuration shown in FIG. 3, in order todecrypt the encryption of the contents, it is necessary to first decryptthe encrypted appending information [Appending Information]Km using themaster key Km so as to take out the contents key Kc 303 contained-inthis appending information, and then decrypt the encrypted contents[Contents] Kc using this contents key Kc.

[0105] This decryption of [Appending Information]Km is carried out atthe license Judgement unit 206. Note that the master key Km fordecrypting the appending information 302 is assumed to be stored insidethe license Judgement unit 206 within this DVD player 101 (for example,the license Judgement unit 206 itself is formed by a semiconductor chipand the master key Km is concealed therein).

[0106] Namely, the master key Km and the appending information encryptedusing the master key Km ([Appending Information]Km) are respectivelyincorporated into the DVD player and the DVD in advance duringmanufacturing processes of the DVD player and the DVD, and managedstrictly such that the master key Km which is the secret key or theencryption scheme using the master key Km will not be leaked out to theexternal.

[0107] As shown in FIG. 3, the appending information also contains areplay condition 304. This replay condition 304 describes a condition tobe satisfied in order to give a permission to the decryption of thecontents by the license Judgement unit 206.

[0108] This condition can be given in a variety of ways, but it isassumed that the replay condition 304 in this embodiment describes atime limit for permitting the decryption of the contents (information ona last limit for permitting the decryption such as “Dec. 31, 1999”, forexample). In other words, the DVD can be replayed (playbacked) as longas this replay condition is satisfied, but the DVD cannot be replayed ifthis replay condition is not satisfied. Note that, in this embodiment,the replay is made impossible by making it impossible to decrypt theencrypted contents unless the replay condition is satisfied.

[0109] Note also that, as will be described in detail later, even whenthe replay condition is not satisfied, it becomes possible to replay theDVD again by carrying out the license updating (by carrying outcommunications with the license server 103 through the telephone network105 in FIG. 1).

[0110] For this reason, it is possible to set this replay condition orthe entire appending information in a RAM region so that it isrewritable by the license Judgement unit 206, and rewrites thecorresponding region by a new updated condition or the replay conditionreflecting a new updated condition when the license updating is carriedout. Here, however, this region should preferably be rewritable only bya special device such as the license Judgement unit 206 and notrewritable by the general DVD-RAM drive.

[0111] Now, in order to replay the contents recorded in the DVD that isset on the DVD drive 207, first, the contents encrypted using thecontents key Kc ([Contents]Kc) 301 and the appending informationencrypted using the master key Km ([Appending Information]Km) areextracted by the contents extraction unit 209 and the appendinginformation extraction unit 208, respectively.

[0112] The appending information encrypted using the master key Km([Appending Information]Km) is then sent to the license judgement unit206. This license judgement unit 206 has the master key Km storedtherein as described above, and takes out the appending information (thecontents key Kc, the replay condition, and the license server address inthe case of FIG. 3) by decrypting the encrypted appending information[Appending Information]Km using the master key Km.

[0113] Next, the license judgement unit 206 checks the replay conditionwithin the decrypted appending information. The license judgement unit206 has a built-in clock therein, and checks the replay condition byjudging whether it is within the valid period or not as described above,for example.

[0114] When the replay condition is satisfied, the license judgementunit 206 judges that the replay is permitted, and the contents key Kcdecrypted using the master key Km is given to the decoder 210 for thefirst time at this point.

[0115] Note however that, as described above, in the case where there isa possibility for exchanging signals between the license judgement unit206 and the decoder 210 (in the case where the license judgement unit206 and the decoder 210 are formed by separate chips, for example), thecontents key Kc should preferably be exchanged in a form [Kc]Ktencrypted using a temporary key Kt that is agreed between the licensejudgement unit 206 and the decoder unit 210 in advance, so as to carryout the exchange of the contents key Kc between the license judgementunit 206 and the decoder 210 safely.

[0116] Namely, in this case, the license judgement unit 206 firstencrypts the contents key Kc using the temporary key Kt and then givesthis [Kc]Kt to the decoder 210, such that the decoder 210 obtains thecontents key Kc by decrypting this [Kc]Kt using the temporary key Kt.

[0117] When the contents key Kc is obtained from the license Judgementunit 206, the decoder 210 decrypts the encrypted contents [Contents]Kcentered from the contents extraction unit 209 using this contents keyKc. Then, the decoder 210 applies a necessary processing such asdecoding to the decrypted contents, and outputs them as video signals oraudio signals, for example.

[0118] Note that the function of this decoder 210 can be set in avariety of ways. For example, when the contents are encrypted afterbeing encoded by MPEG2 or the like, the decoder 210 can decrypt anddecode [Contents]Kc and output them after the conversion into. NTSCsignals or else output them in a state of being encoded by MPEG2 or thelike. Also, when the contents are image data, the decoder 210 can outputthem after the conversion into bit map data.

[0119] When the replay condition is not satisfied as a result ofchecking the replay condition at the license Judgement unit 206 (thecase where the valid period has expired in this example), it impliesthat the license is not valid (the license has expired in this example).For this reason, the license Judgement unit 206 displays a messageindicating that the license has expired, for example, and upon obtaininga permission of a user by receiving an input of a command indicatingthat the license updating is to be carried out from the user, thelicense judgement unit 206 attempts to update the license. Here however,when a command indicating that the license updating is not to be carriedout is entered from the user, the processing regarding these contentswill be terminated at this point.

[0120] Next, the case where the replay condition is not satisfied as aresult of checking the replay condition at the license Judgement unit206 and the license is to be updated will be described.

[0121] When the license is to be updated, the actual license updateprocedure is carried out by the license update procedure unit 205.

[0122] First, the license update procedure unit 205 checks the licenseserver address 305 in the appending information 302 decrypted at thelicense Judgement unit 206, where an address of the license server to beaccessed in the case of carrying out the license updating is described.

[0123]FIG. 4 shows an exemplary format of the license server addressdescription. In FIG. 4, the license server address comprises an addresstype section and an address section. The address type section describesa name of address system to be used (or a name of network system usingthat address system) such as telephone number (or telephone network), IPaddress, ATM address, JAVA name space, CORBA name space, or domain name,for example. The address section describes the actual address. Note thatthis description may be standardized using URL (Uniform ResourceLocator). Note also that, in FIG. 4, the license server addresses may bedescribed in their priority orders, in which case the address givencloser to the top should be tried earlier.

[0124] In this embodiment, a connection with one of the addressesdescribed in the license server address 305 in the appending information302 is established and the license update procedure using a prescribedprotocol is carried out between the license server and this DVD player101.

[0125] Here, when this DVD player 101 is assumed to be not having the IPprotocol as a protocol stack, it is impossible to carry outcommunications using IP addresses, so that the telephone number is to beselected. Else, in the case of trying the license server address closerto the top earlier in FIG. 4, the telephone number is going to beselected first.

[0126] Now the license update procedure unit 205 refers to thisinformation of the license server address and select one, and then givesthe selected address information to the telephone server procedure unit204 so as to request the connection set up.

[0127] Upon receiving this request for connection set up, the telephoneserver procedure unit 204 attempts to establish the connection with thelicense server 103 according to a prescribed procedure. FIG. 5 shows anexemplary connection set up procedure by the telephone server procedureunit 204.

[0128] The telephone server procedure unit 204 first checks whether thetelephone modem is connected to the own device or not and whether thetelephone cable is connected to that telephone modem or not, in anattempt to directly make a telephone call to the described telephonenumber (step S501).

[0129] If the telephone modem 201 is connected to the own device and thetelephone cable is connected to the telephone modem 201 so that thetelephone network 105 is utilizable (step S501 YES), the telephoneserver procedure unit 204 attempts to establish the telephone connectionwith the license server 103 through the telephone modem 201, and whenthe connection is established, the license update procedure unit 205carries out communications with the license server 103 through theinterface selection unit 203, the telephone modem 201 and the telephonenetwork 105, so as to carry out the license update procedure accordingto a protocol determined between the DVD player 101 and the licenseserver 103 in advance (step S502).

[0130] If the telephone modem 201 is not connected, or the telephonecable is not connected to the telephone modem 201, or else the telephonemodem 201 is not connected to the telephone network 105 (step S501 NO),the telephone server procedure unit 204 checks whether the 1394 cable isconnected to the IEEE 1394 interface 202, in an attempt to establish theconnection using the telephone server (step S503).

[0131] If the 1394 cable is not connected to the IEEE 1394 interface202, it implies that the DVD player 101 cannot make an access to thelicense server 103, so that it is Judged that the communications withthe license server 103 are impossible and therefore the license updatingis abandoned, and the fact that the updating is impossible (or a messagefor urging the user to connect the telephone cable or the 1394 cable) isnotified to the user (step S505).

[0132] If the 1394 cable is connected (step S503 YES), whether thetelephone server (whose function is provided by the home gateway 102 inthis embodiment) exists on this IEEE 1394 bus or not is investigated. Aswill be described later, this investigation as to whether or not thetelephone server exists can be realized by reading the IEEE 1212register of a device on the IEEE 1394 bus or by executing the servicelocation protocol (step S506).

[0133] This telephone server is connected with both the home network 104and the telephone network 105, and mediates communications between adevice connected to the home network 104 and a device connected at alocation that can be reached through the telephone network 105. Namely,this telephone server provides a mechanism for transparently realizingdata communications between a device connected to the telephone network105 either directly or through other networks (the license server 103 inthis embodiment) and a device connected to the home network 104 (the DVDplayer 101 in this embodiment). The further detail of this telephoneserver will be described later.

[0134] If the telephone server does not exist on the IEEE 1394 bus (stepS504 NO), similarly as in the case of step S503 NO described above, itimplies that the DVD player 101 cannot make an access to the licenseserver 103, so that it is judged that the communications with thelicense server 103 are impossible and therefore the license updating isabandoned, and the fact that the updating is impossible (or a messagefor urging the user to connect the telephone cable or activate thetelephone server) is notified to the user (step S505).

[0135] If the telephone server exists on the IEEE 1394 bus (step S504YES), the telephone server procedure unit 204 requests the home gateway102 to establish the connection with the license server 103 through theIEEE 1394 interface 202 and the IEEE 1394 bus 104, and when theconnection is established, the license update procedure unit 205 carriesout communications with the license server 103 through the interfaceselection unit 203, the IEEE 1394 interface 202, the IEEE 1394 bus 104and the home gateway 102, so as to carry out the license updateprocedure (step S506).

[0136] Note that the concrete contents of the license update proceduredepends on the license server, but basically, the license updateprocedure includes exchanging an information for the charging or thelicense contract and receiving an information for enabling theutilization or the processing of the contents such as a new replaycondition in the case of this embodiment.

[0137] Now, after the license update procedure is completed as describedabove, the fact that the license updating is completed as well as a newreplay condition are notified from the license update procedure unit 205to the license judgement unit 206.

[0138] Then, the license judgement unit 206 carries out a processing forupdating the replay condition for this DVD to the new replay condition.For example, the item regarding the replay condition among the appendinginformation read out from the DVD on the DVD drive 207 and decrypted isrewritten according to the updating made with the license server, andthe appending information after this updating is encrypted using themaster key Km and stored into an appropriate region in the DVD again.Else, this updated information is stored by this DVD player 101 itselfsuch that the replay condition is Judged according to this updatedreplay condition whenever the same DVD (having the same disk ID forexample) is set on the DVD drive 207 subsequently.

[0139] Also, the license judgement unit 206 permits the replay, andgives the contents key Kc decrypted using the master key Km to thedecoder 210. Then, as described above, the decoder 210 decrypts theencrypted contents [Contents]Kc using the received contents key Kc,decodes these contents if necessary, and output them as video signals oraudio signals, for example.

[0140] Next, with references to FIG. 6, FIG. 7 and FIG. 8, thecommunication sequence will be described. FIG. 6 shows an exemplarycommunication sequence, FIG. 7 shows an exemplary operation sequence ofthe DVD player, and FIG. 8 shows an exemplary operation sequence of thehome gateway.

[0141] This communication sequence is executed in the case of where theDVD player 101 carries out communications with the license server 103through the telephone server (i.e., the home gateway 102) in the abovedescribed procedure. Namely, it is the case where the DVD player 101wishes to communicate with the license server 103 through the homegateway 102 and carry out the license update procedure.

[0142] First, the DVD player 101 reads and checks the contents of theIEEE 1212 register of a device existing on the IEEE 1394 bus 104, so asto detect a device having the function of the telephone server (stepS601 of FIG. 6, step S701 of FIG. 7). Here it is assumed that theaddress of the IEEE 1212 register is determined among devices connectedto the IEEE 1394 bus in advance and the IEEE 1212 register registersinformation regarding functions of that device or services provided bythat device. Note that this detection can also be realized by using theservice location protocol instead of using the IEEE 1212 register asdescribed above. The service location protocol is a protocol fordetecting or notifying a certain service on the network in the protocolsuch as Internet protocol. The detail of the service location protocolcan be found in RFC 2165.

[0143] As for the home gateway 102, the fact that the own devicefunctions as the telephone server is registered into the IEEE 1212register in advance by a procedure as shown in FIG. 9. Namely, when atelephone server process is activated on the own device and a telephonecable is connected to a telephone network interface (telephone modem) ofthe own device so that communications with the telephone network 105 ispossible (steps S901 and S902), it is Judged that the own device iscapable of operating as the telephone server, and the fact that the owndevice has a function of the telephone server is registered into the ownIEEE 1212 register (step S801 of FIG. 8, step S903 of FIG. 9).

[0144] By registering the fact that the own device functions as thetelephone server in the IEEE 1212 register in this way, it becomespossible to notify the fact that the own device functions as thetelephone server to devices connected to the IEEE 1394 bus 104.

[0145] Now, when the existence of the telephone server (the home gateway102 has the function of the telephone server in this embodiment) on theIEEE 1394 bus 104 is recognized (step S702 of FIG. 7), the DVD player101 makes a telephone call to the address (telephone number) of thelicense server that is read out from the appending information earlier,in an attempt to carry out the license update procedure. In order toattempt this through the IEEE 1394 bus 104 which is the home network,the DVD player 101 sends a call set up solicitation to the home gateway102 (step S602 of FIG. 6, step S704 of FIG. 7). This call set upsolicitation implies soliciting the home gateway 102 like “please make atelephone call to the telephone number #X with respect to the telephonenetwork”.

[0146] Also, in order to carry out communications through a telephonechannel established in response to this solicitation subsequently, atransaction number is also defined at the same time, in a sense ofnaming this telephone channel (or session). Namely, the informationindicating address type=POTS (Plain Old Telephone System: telephonenetwork), address=#x, and transaction number=α is transferred from theDVD player 101 to the home gateway 102.

[0147] Upon receiving the call set up solicitation (step S802 of FIG.8), the home gateway 102 sends a call set up request to the telephonenetwork 105 based on this solicitation (step S603 of FIG. 6, step S803of FIG. 8). This call set up request is made with respect to thetelephone number contained in the call set up solicitation receivedearlier.

[0148] When this call set up succeeds, a call set up success (CONNECT)message is returned from the telephone network 105 side (step S604 ofFIG. 6).

[0149] Upon receiving the call set up success message (step S804 of FIG.8), the home gateway 102 notifies the successful connection with thelicense server 103 to the DVD player 101 along with the transactionnumber (α) (step S605 of FIG. 6, step S806 of FIG. 8).

[0150] Upon receiving this notification (step S605 of FIG. 6, step S705of FIG. 7), the DVD player 101 carries out communications regarding thelicense updating with the license server 103 according to a protocolprocedure determined between the DVD player 101 and the license server103 in advance (step S606 of FIG. 6, step S707 of FIG. 7, steps S807 andS808 of FIG. 8). Here, in the communications regarding the licenseupdate procedure, data to be exchanged should preferably be encryptedusing a network key Kn. This network key Kn is an encryption key that isagreed between the DVD player 101 and the license server 103 in advance.Note that this network key Kn is assumed to be a secret key here, but itis also possible to use a public key.

[0151] In the case of carrying out data exchange between the DVD player101 and the license server 103, the home gateway (telephone server) 102carries out the modem processing as indicated in FIG. 6.

[0152] Namely, data to be transmitted from the DVD player 101 to thelicense server 103 are sent as ordinary digital signals according to theIEEE 1394 standard up to the home gateway 102. Then, at the home gateway102, these signals are modulation processed and sent through thetelephone network 105 so as to carry out communications with the licenseserver 103. As for data to be transmitted from the license server 103 tothe DVD player 101, the modulated telephone signals are sent through thetelephone network 105 up to the home gateway 102. Then, at the homegateway 102, these signals are demodulated and sent to the DVD player101 as IEEE 1394 signals.

[0153] Here, from a viewpoint of the DVD player 101 and the licenseserver 103, it appears that a protocol for carrying out the licenseupdate procedure is operating and a difference in the physical layerssuch as the above described modem processing is concealed. In otherwords, a difference in the physical layers is concealed by inserting themodem processing between the physical layers at the home gateway 102.

[0154] Note that, when the DVD player 101 fails to detect the telephoneserver function on the IEEE 1394 bus 104, the DVD player 101 cannot makea telephone call so that the communications with the license server 103become impossible and the processing is terminated there (step S703 ofFIG. 7).

[0155] Also, when the call set up at the home gateway 102 fails, thehome gateway notifies the DVD player 101 that the further processing isimpossible (step S805 of FIG. 8), and when this notification isreceived, the DVD player 101 also cannot make a telephone call so thatthe processing is terminated there (step S706 of FIG. 7).

[0156] Next, FIG. 10 shows an exemplary internal configuration of thehome gateway 102 for providing the service as described above.

[0157] As shown in FIG. 10, the home gateway 102 comprises an IEEE 1394interface 1001, a service notification unit 1002, a filter unit 1003, atelephone server unit 1004, a data modulation/demodulation unit 1005,and a telephone network interface 1006.

[0158] The function of the home gateway 102 as the telephone server iscontained in the telephone server unit 1004, that is, the telephoneserver unit 1004 controls the sequence of FIG. 8.

[0159] The IEEE 1394 interface 1001 is an interface to the IEEE 1394 bus104, and the telephone network interface 1006 is an interface to thetelephone network 105.

[0160] The service notification unit 1002 has a function for notifyingthat the own device has the function of the telephone server, throughthe IEEE 1394 interface 1001, which is realized by the IEEE 1212register in this embodiment.

[0161] The data modulation/demodulation unit 1005 carries out the modemprocessing shown in FIG. 6.

[0162] The filter unit 1003 extracts the license update procedure dataamong data entered through the IEEE 1394 interface 1001, and shares theextracted license update procedure data with the datamodulation/demodulation unit 1005.

[0163] Under the control of the telephone server unit 1004, thetransparent data communications between the DVD player 101 and thelicense server 103 are provided by the operation of the filter unit 1003and the data modulation/demodulation unit 1005.

[0164] In this way, the DVD player becomes capable of carrying outcommunications with the license server on the public network. Namely, itbecomes possible for this DVD player to carry out communications withthe license server on the public network without directly connecting thetelephone line to the DVD player, so that it becomes unnecessary todirectly connect the telephone line to the DVD player as requiredconventionally. Consequently, when the wirings for the IEEE 1394 areprovided and the telephone server (the home gateway 102 in thisembodiment) exists on the IEEE 1394, it is unnecessary to providewirings for the telephone line so that a considerable simplification ofwirings becomes possible.

[0165] Now, in the description up to this point, it has been assumedthat the protocol for the license update procedure to be used is aprotocol that is agreed between the DVD player 101 and the licenseserver 103 in advance. In this case, there is a need to activate thecommon protocol for the license update procedure at every DVD player.

[0166] For this reason, as shown in FIG. 11, it is also possible toinclude the protocol program for the license update procedure(communication protocol program for license server) 1106 in theappending information that is contained in the DVD, in an expectation ofa presence of a common interface such as JAVA virtual machine in the DVDplayer. In such a case, it becomes possible to select the license updateprocedure protocol for each license server, by downloading the abovedescribed protocol program for the license update procedure that iscontained in the appending information of the DVD into the JAVA virtualmachine and letting this program to carry out the license updateprocedure when the license update procedure becomes necessary. In thiscase, this protocol processing program will be described in JAVA, andthis processing protocol will be described using the standard APIdefined on the JAVA virtual machine.

[0167] Also, as shown in FIG. 12, it is possible to provide a pluralityof protocol processing programs written in a plurality of programminglanguages, and change the program to be downloaded depending on thesoftware platform of the DVD player. In FIG. 12, the protocol processingprograms are written in the programming languages such as JAVA andvisual basic script so that it is possible to deal with the case wherethe software platform of the DVD player is the JAVA virtual machine aswell as the case where the software platform of the DVD player is a PCmounted with the Windows which is the OS of the Microsoft Corporation.In this way, even in the case where it is not necessarily possible toexpect the unification of the software platform as in the case of PCs,it becomes possible to provide a plurality of programs so that theflexible handling becomes possible.

[0168] Also, as shown in FIG. 13, it is possible to leave the licenseserver address in plaintext without encrypting it and attach anauthenticator 1306 for this address in order to prove the authenticityof this address. Namely, an information obtained by encrypting thelicense server address or the “digest information” produced by applyingthe hash function such as MD5 to the license server address, using themaster key Km for example, can be attached to the license server address1305 as the authenticator 1306.

[0169] The processing for recognizing the license server address at theDVD player at a time of playbacking the DVD can be as follows, forexample.

[0170] First, the authentication scheme is assumed to be agreed betweenthe DVD manufactures and the DVD players in advance. Here, the DVDplayer takes out the license server address 1305 of the appendinginformation 1302, and executes a procedure that is agreed upon inadvance (such as a procedure for generating the authenticator from thelicense server address as described above). When the result is identicalto the value of the address authenticator 1306, it is recognized thatthis address information is surely a proper one, and the addressinformation written therein is recognized as the license server address.The reason why this address information can be recognized as a properone is that it is possible to interpret that this authenticator can beproduced only by someone who knows the value of the master key Km, sothat it is possible to interpret that someone who is capable of knowingthe master key Km in advance and therefore trustworthy has produced thislicense server address 1305.

[0171] Note that the above description has been directed to the casewhere the DVD player has an architecture having both the public networkinterface (telephone modem 201) and the local network interface (IEEE1394 interface 202) as shown in FIG. 2, but it is also possible to use aconfiguration which only has the local network interface 202 and doesnot have the public network interface as shown in FIG. 14, for example.In other words, this is a configuration in which the operation startsfrom the step S503 of FIG. 5 as it only has the IEEE 1394 interfacealone. In this configuration, it is unnecessary to provide the publicnetwork interface so that the manufacturing cost can be reducedconsiderably.

[0172] Note also that the above description has been directed to thecase of using the DVD player as an example, but the present invention isequally applicable to the variety of other devices such as VTR, TV,computer, etc.

[0173] Note also that the above description has been directed to thecase where the device such as DVD player is directly connected to thelocal network, but the present invention is equally applicable to thecase where the device such as DVD player is connected to the localnetwork indirectly through another local network instead of beingdirectly connected to the local network.

[0174] Note also that the above description has been directed to thecase of using the IEEE 1394 as the local network, but it is alsopossible to use any other network such as Ethernet, ATM-LAN, power linenetwork, radio network, etc.

[0175] Note also that the above description has been directed to thecase of using the telephone network as the network other than the localnetwork, but it is also possible to use any other network such asanother local network, another public network, Internet, PC network,etc.

[0176] Note also that the above description has been directed to thecase of using the DVD as a storage medium, but the present invention isequally applicable to any other storage media.

[0177] Note also that the above description has been directed to thecase of giving permission for the contents utilization per disk, but itis also possible to control the utilization and carry out the procedurefor obtaining a permission per content within the disk.

[0178] Note also that the above description has been directed to thecase of carrying out the encryption and the decryption using the masterkey Km, but it is also possible to use any key other than the master keyKm as long as it is agreed between the suppliers of the DVD or the likeand the DVD player or the like in advance. It is also obviously possibleto use the public key cryptosystem. The present invention is alsoapplicable to the case where a plurality of contents are stored in onestorage medium and the encryption using different keys is to be appliedto different contents. The present invention is also applicable to thecase where a plurality of contents are stored in one storage medium anddifferent replay conditions are given to different contents. Also, inthe case of using the authenticator as shown in FIG. 14, it is possibleto use different keys for the encryption of the contents and thegeneration of the authenticator.

[0179] As described, according to the present invention, the contentsprocessing device connected to the external network such as thetelephone network solicits the mediation of communications through theexternal network to the gateway device which is located on the localnetwork such as the home network and which is connected to the externalnetwork, such that the contents processing device can carry outcommunications through the external network even when the contentsprocessing device has no interface to the external network.

[0180] Also, as a consequence, the wirings and the network interface tobe provided in the contents processing device for this purpose can beonly those related to the local network so that it is possible tosimplify the wirings and the contents processing device configuration.

[0181] It is to be noted that, besides those already mentioned above,many modifications and variations of the above embodiments may be madewithout departing from the novel and advantageous features of thepresent invention. Accordingly, all such modifications and variationsare intended to be included within the scope of the appended claims.

What is claimed is:
 1. A gateway device, comprising: a first networkinterface for connection to a home network; a second network interfacefor connection to a telephone network; a call set up unit for carryingout a call set up with respect to a specified address on the telephonenetwork, upon receiving a solicitation for the call set up with respectto the specified address on the telephone network from a contentsprocessing device connected to the home network; and a transfer unit fortransferring data transmitted from the contents processing device to aconnection established by the call set up, and data arriving from theconnection established by the call set up to the contents processingdevice.
 2. The gateway device of claim 1, wherein the call set up unitreceives the solicitation made by the contents processing device whichhas a need to communicate with the specified address in order to processa specific contents information.
 3. The gateway device of claim 1,further comprising: a notification unit for notifying that the gatewaydevice is in a state capable of responding to the solicitation, throughthe home network.
 4. A contents processing device, comprising: a networkinterface for connection to a home network; a protocol processing unitfor executing protocol processing for communications with a serverdevice through a telephone network; a solicitation unit for soliciting aset up of connection to the server device through the telephone network,to a gateway device which is connected with both the home network andthe telephone network; and a contents processing unit for processingcontents information according to the communications with the serverdevice.
 5. The contents processing device of claim 4, furthercomprising: an additional network interface for connection to thetelephone network; and a judgement unit for judging whether thecommunications with the server device through the additional networkinterface is possible or not; wherein the solicitation unit solicits theset up of connection to the server device through the telephone networkand the protocol processing unit carries out the communications with theserver device through the gateway device, when the judgement unit Judgedthat the communications with the server device through the additionalnetwork interface is not possible.
 6. The contents processing device ofclaim 4, wherein the protocol processing unit carries out a prescribedprocedure using the communications with the server device in order toobtain a permission to process a specific contents information, when aneed to obtain a permission to process the specific contents informationarises.
 7. The contents processing device of claim 6, wherein thecontents processing unit reads out the specific contents informationfrom a prescribed storage medium, and the protocol processing unitobtains an address information of the server device which is to be usedin setting up connection to the server device, which is recorded alongwith the specific contents information in the prescribed storage medium.8. The contents processing device of claim 7, wherein the protocolprocessing unit authenticates the address information using anauthentication information for the address information which is alsorecorded in the prescribed storage medium, before obtaining the addressinformation.
 9. The contents processing device of claim 7, wherein theprotocol processing unit obtains the address information by decryptingan encrypted address information which is recorded in the prescribedstorage medium.
 10. The contents processing device of claim 6, whereinthe protocol processing unit executes the protocol processing byexecuting a communication protocol program which is recorded in theprescribed storage medium along with the specific contents information.11. The contents processing device of claim 10, wherein the protocolprocessing unit executes the communication protocol program bydecrypting an encrypted communication protocol program which is recordedin the prescribed storage medium.
 12. The contents processing device ofclaim 6, wherein the protocol processing unit executes the protocolprocessing by executing one communication protocol program that isexecutable at the contents processing device among a plurality ofcommunication protocol programs of identical function written indifferent programming languages which are recorded in the prescribedstorage medium along with the specific contents information.
 13. Thecontents processing device of claim 12, wherein the protocol processingunit executes said one communication protocol program by decrypting acorresponding one encrypted communication protocol program which isrecorded in the prescribed storage medium.
 14. The contents processingdevice of claim 4, wherein the contents processing unit utilizescontents information recorded in a prescribed storage medium when areplay condition recorded in the prescribed storage medium is satisfiedor when a permission regarding contents information utilization isobtained through a prescribed procedure.
 15. The contents processingdevice of claim 14, further comprising: an extraction unit forextracting an address information of the server device to becommunicated with in order to obtain the permission when the replaycondition recorded in the prescribed storage medium is not satisfied;wherein the solicitation unit solicits the set up of connection to theserver device according to the address information extracted by theextraction unit, and the protocol processing unit carries out theprescribed procedure for obtaining the permission from the server devicethrough the connection established by the gateway device in response toa solicitation by the solicitation unit.
 16. The contents processingdevice of claim 15, wherein the protocol processing unit carries out theprescribed procedure by executing a communication protocol program whichis recorded in the prescribed storage medium along with the contentsinformation.
 17. A gateway device, comprising: a first network interfacefor connection to a local network; a second network interface forconnection to an external network; a connection set up unit for carryingout a connection set up with respect to a specified address on theexternal network, upon receiving a solicitation for the connection setup with respect to the specified address on the external network from acontents processing device connected to the local network; and atransfer unit for transferring data transmitted from the contentsprocessing device to a connection established by the connection set up,and data arriving from the connection established by the connection setup to the contents processing device.
 18. A contents processing device,comprising: a network interface for connection to a local network; aprotocol processing unit for executing protocol processing forcommunications with-a server device through an external network; asolicitation unit for soliciting a set up of connection to the serverdevice through the external network, to a gateway device which isconnected with both the local network and the external network; and acontents processing unit for processing contents information accordingto the communications with the server device.
 19. A gateway device,comprising: a first network interface for connection to a first network;a second network interface for connection to a second network differentfrom the first network; a connection set up unit for carrying out aconnection set up with respect to a specified address on the secondnetwork, upon receiving a solicitation for the connection set up withrespect to the specified address on the second network from a contentsprocessing device connected to the first network; and a transfer unitfor transferring data transmitted from the contents processing device toa connection established by the connection set up, and data arrivingfrom the connection established by the connection set up to the contentsprocessing device.
 20. A contents processing device, comprising: anetwork interface for connection to a first network; a protocolprocessing unit for executing protocol processing for communicationswith an external device through a second network different from thefirst network; a solicitation unit for soliciting a set up of connectionto the external device through the second network, to a gateway devicewhich is connected with both the first network and the second network;and a contents processing unit for processing contents informationaccording to the communications with the external device.